U.S. Pat. No. 1,707,331, issued Apr. 2, 1929, discloses the use as methanol synthesis catalysts of copper in combination with fluorides of the cerium family. There is no mention of a zinc aluminate support.
U.S. Pat. No. 3,758,417, issued Sept. 11, 1973, to Magoon et al, discloses a copper, zinc, didymium oxide-containing catalyst which is particularly useful for converting carbon oxides and hydrogen to methanol. This catalyst is prepared by co-precipitation of nitrates at a temperature of about 85.degree. C.-90.degree. C. This reference does not disclose the use of a zinc aluminate support.
U.S. Pat. No. 3,950,369, issued Apr. 13, 1976, discloses a methanol catalyst comprising copper, zinc and a Group II to IV element. The disclosure herein is a generic disclosure with no special preparative techniques indicated.
U.S. Pat. No. 3,923,694 issued Dec. 2, 1975, teaches the use of a zinc aluminate spinel substrate with copper or copper/zinc supported thereon.
U.S. Pat. No. 4,181,630, issued Jan. 1, 1980, discloses a methanol synthesis catalyst comprising copper in combination with an oxide of a rare earth, an actinide element, titanium, zirconium or hafnium. No special preparative techniques are indicated herein. Generally the catalysts are made by first preparing a metal alloy and then oxidizing the alloy to appropriate oxide.
U.S. Pat. No. 4,308,176, issued Dec. 29, 1981, discloses a methanol synthesis catalyst comprising copper mixed with an oxide matrix. In this reference a copper-aluminum oxide spinel is first formed and zinc oxide is subsequently added. Particular care is taken to avoid formation of zinc aluminate spinel.
U.S. Pat. No. 4,319,037, issued Mar. 9, 1982, discloses a catalyst for converting methanol to methyl formate. This catalyst comprises copper plus a Group IIIB or Group IVB or rare earth or actinide element. No particular critical preparative techniques are disclosed, nor is a zinc aluminate spinel support mentioned.
Japanese Patent No. 54 [1979]-26983 published Feb. 28, 1979, discloses as a methanol catalyst a copper, zinc, lanthanum catalyst. This catalyst is prepared by precipitation with alkali metal carbonates. No suggestion of a zinc aluminate spinel support is mentioned.
German Patent No. 3,005,551, published Feb. 14, 1980, discloses a methanol synthesis catalyst comprising copper, zinc and a promoter selected from chromium, cerium, lanthanum, manganese and/or thorium. It is stated that these compounds may be added at any stage in the preparation of the catalyst. It is further stated that addition of compounds such as aluminum oxide lowers catalytic activity.
In application Ser. No. 487,081 filed Apr. 27, 1983, now abandoned, there is disclosed a process for preparing methanol catalysts using alkali metal carbonates as precipitating agents to precipitate copper, zinc and modifier salts at controlled pH levels ranging between about 5.5 and 7.5.
In application Ser. No. 503,984, filed June 13, 1983, now abandoned, there is disclosed a process for preparing methanol catalysts using ammonium carbonate as a precipitating agent to precipitate copper, zinc and modifies salts at controlled pH levels ranging between about 5.5 and 7.5.